Snare-type animal traps are well known in the prior art. Examples of such traps used as leg snares can be found in U.S. Pat. No. 3,060,623 to Aldrich, U.S. Pat. No. 4,286,404 to Novak, et al., and Canadian Patent No. 1,108,853 to Novak. These leg snare animal traps are characterized by a spring-biased spring arm which pivots upwardly when the trap is sprung to tighten a cable noose around the leg of the trapped animal. The cable is anchored at one end and has the noose at the other end. An intermediate portion of the cable is slidably guided at the distal end of the spring arm so that the noose can be tightened by the sprung spring arm. The cable must be readily removable from the guide by the resisting forces of the trapped animal so that the trap mechanism becomes free of the cable and is less likely to be damaged by the animal.
It is important in such leg snare traps that the spring arm be able to very quickly tighten the cable noose about the animal's leg when the trap is sprung in order to assure that the animal cannot escape. This requires that the spring arm move quickly through as large an angle as possible while pulling the loosely held cable in slidable engagement in the cable guide. It also requires that the cable noose rise vertically very quickly with the spring arm so that the cable does not fall out of the guide member. Moreover, it is important that the snare trap mechanism be sufficiently sturdy so that a trapped animal cannot permanently damage the mechanism even after it has been disengaged from the cable.
The trap disclosed in the Aldrich patent is fabricated from a plurality of steel rods which can be bent and distorted to preclude re-use. Moreover, Aldrich employs a U-shaped cable guide at the distal end of the spring arm which can result in inadvertent disengagement of the cable prior to or during the springing action of the trap. Specifically, the open end of the U-shaped guide member faces to the side, relative to the vertical spring arm pivot plane, so that the cable can readily be dis-lodged from the open side of the guide member.
The Novak, et al. U.S. patent and the Novak Canadian patent provide a more durable and damageresistant structure by providing a base on top of which a coiled torsion spring is mounted. The spring arm is pivotable by the spring and is rotatable relative to the base plate. In order to achieve a spring arm rotation sufficient to reliably and quickly tighten the cable noose, the Novak and Novak, et al. devices require a spring having in excess of ten (10) turns. In addition, the guide member forms at the distal end of the spring arm is in the form of a saddle with short upwardly-extending sides over which the cable can readily be pulled, resulting in undesirable disengagement of the cable from the trap mechanism.
Neck snare traps are similar in many respects to leg snare traps but are intended to quickly tighten about the neck, rather than the leg, of the trapped animal. In this respect, the noose of the neck snare is placed in a path or trail normally traveled by animals to be trapped such that a moving animal's head can enter and pull on the noose so as to actuate the trap. It is very important in a neck snare that the spring arm move quickly through as large an angle as possible while pulling the noose tightly around the neck of the trapped animal. More specifically, the neck snare is intended to kill the trapped animal and, therefore, the noose should tighten substantially instantly in order to assure a rapid and humane death. Examples of prior art neck snare traps may be found in U.S. Pat. Nos. 1,647,578 (Penn) and 3,958,360 (King).
The neck snare disclosed in the Penn patent relies on the resilience of a support pole, which is bent or flexed when the trap is set, in order to pull the noose about the animal's neck. In practice, the time required for the noose to tighten is much too long to be considered humane.
The snare disclosed in the King patent employs a spring-loaded pivotable bar or rod which pivots and pulls on the noose when the trap is sprung. The noose is tightened more quickly than is the case in the Penn device; however, it still does not effect the desired rapid and humane death.